INFO: task syz.0.9286:12239 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.9286 state:D stack:25960 pid:12239 tgid:12238 ppid:10052 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x17dd/0x5820 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7474
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7531
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821
nfsd_nl_rpc_status_get_dumpit+0xf0/0x1560 fs/nfsd/nfsctl.c:1521
genl_dumpit+0x10b/0x1b0 net/netlink/genetlink.c:1026
netlink_dump+0x711/0xee0 net/netlink/af_netlink.c:2351
__netlink_dump_start+0x589/0x7b0 net/netlink/af_netlink.c:2466
genl_family_rcv_msg_dumpit+0x213/0x310 net/netlink/genetlink.c:1075
genl_family_rcv_msg net/netlink/genetlink.c:1191 [inline]
genl_rcv_msg+0x5e1/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2576
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
netlink_unicast+0x8ef/0xa80 net/netlink/af_netlink.c:1361
netlink_sendmsg+0x7f0/0xb20 net/netlink/af_netlink.c:1920
sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800
__sock_sendmsg net/socket.c:818 [inline]
____sys_sendmsg+0x54e/0x850 net/socket.c:2715
___sys_sendmsg+0x2a5/0x360 net/socket.c:2769
__sys_sendmsg net/socket.c:2801 [inline]
__do_sys_sendmsg net/socket.c:2806 [inline]
__se_sys_sendmsg net/socket.c:2804 [inline]
__x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2804
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8190d9f559
RSP: 002b:00007f8191bd5028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f8191025fa0 RCX: 00007f8190d9f559
RDX: 0000000000000080 RSI: 0000200000000300 RDI: 0000000000000006
RBP: 00007f8190e36b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8191026038 R14: 00007f8191025fa0 R15: 00007ffdd8b514e8
Showing all locks held in the system:
locks held by khungtaskd/33: 1, last CPU#0:
#0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by dhcpcd/5293: 1, last CPU#0:
#0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#0: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by getty/5389: 2, on CPU#1:
#0: ffff8880335b10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032432e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by kworker/u8:59/25643: 7, last CPU#1:
#0: ffff88801c0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88801c0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88801c0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff88801c0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc90004f27c40 ((work_completion)(&port->bc_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90004f27c40 ((work_completion)(&port->bc_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90004f27c40 ((work_completion)(&port->bc_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc90004f27c40 ((work_completion)(&port->bc_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#2: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#2: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#2: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: macvlan_process_broadcast+0x2e7/0x650 drivers/net/macvlan.c:343
#3: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#3: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#3: ffffffff8fd59ca0 (rcu_read_lock){....}-{1:3}, at: netif_receive_skb_core+0x33/0x2b0 net/core/dev.c:6429
#4: ffffffff8fd59d00 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#4: ffffffff8fd59d00 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:902 [inline]
#4: ffffffff8fd59d00 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x29b/0x3920 net/core/dev.c:4980
#5: ffffffff9bc5b008 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0xb7/0x420 lib/debugobjects.c:873
#6: ffff88804b420f40 (&lapbeth->up_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:353 [inline]
#6: ffff88804b420f40 (&lapbeth->up_lock){+.-.}-{3:3}, at: lapbeth_xmit+0x32/0x260 drivers/net/wan/lapbether.c:191
locks held by syz.4.9253/12094: 2, on CPU#0:
#0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff9009e720 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x53d/0x1ab0 fs/nfsd/nfsctl.c:2057
locks held by syz.0.9286/12239: 3, on CPU#1:
#0: ffffffff912db128 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffff88807a3286f0 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xf4/0x7b0 net/netlink/af_netlink.c:2430
#2: ffffffff9009e720 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xf0/0x1560 fs/nfsd/nfsctl.c:1521
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 33 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd2/0x1030 kernel/hung_task.c:561
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 25643 Comm: kworker/u8:59 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Workqueue: events_unbound macvlan_process_broadcast
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x5b/0xb0 kernel/rcu/tree.c:753
Code: f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 fb 8c 8c 00 48 c7 c3 98 8d 9c 94 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 <84> c0 75 35 8b 03 65 48 ff 0d 17 7f ee 12 74 11 83 e0 04 c1 e8 02
RSP: 0018:ffffc90000a08740 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: ffff8880b8533d98 RCX: 0000000000000102
RDX: 00000000e61b7dd1 RSI: ffffffff8c6e1760 RDI: ffffffff8c6e1720
RBP: 1ffff92000141108 R08: ffffffff8178699f R09: 0000000000000000
R10: ffffc90000a08858 R11: ffffffff81b301f0 R12: dffffc0000000000
R13: ffffffff8178699f R14: ffffffff8e75a7d8 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888123b6b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561406381660 CR3: 000000007f692000 CR4: 00000000003526f0
Call Trace:
rcu_read_lock include/linux/rcupdate.h:850 [inline]
class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
unwind_next_frame+0xbe/0x2550 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:264 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:296
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2748 [inline]
slab_free mm/slub.c:6509 [inline]
kfree+0x1c5/0x650 mm/slub.c:6802
skb_release_all net/core/skbuff.c:1188 [inline]
__kfree_skb+0x5d/0x210 net/core/skbuff.c:1202
kfree_skb_reason include/linux/skbuff.h:1329 [inline]
kfree_skb include/linux/skbuff.h:1338 [inline]
x25_lapb_receive_frame+0x66/0xfb0 net/x25/x25_dev.c:143
__netif_receive_skb_one_core net/core/dev.c:6405 [inline]
netif_receive_skb_core+0x2a6/0x2b0 net/core/dev.c:6430
lapbeth_napi_poll+0x42/0x90 drivers/net/wan/lapbether.c:100
__napi_poll+0xaa/0x330 net/core/dev.c:7938
napi_poll net/core/dev.c:8001 [inline]
net_rx_action+0x61d/0xf50 net/core/dev.c:8158
handle_softirqs+0x265/0x8d0 kernel/softirq.c:669
do_softirq+0x77/0xd0 kernel/softirq.c:569
__local_bh_enable_ip+0x100/0x140 kernel/softirq.c:473
local_bh_enable include/linux/bottom_half.h:33 [inline]
netif_rx+0x89/0xa0 net/core/dev.c:5978
macvlan_broadcast+0x375/0x630 drivers/net/macvlan.c:292
macvlan_multicast_rx drivers/net/macvlan.c:-1 [inline]
macvlan_process_broadcast+0x437/0x650 drivers/net/macvlan.c:344
process_one_work kernel/workqueue.c:3495 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245